Despite poor approval ratings for the president in Iowa, the Democratic candidate for Senate led all of his potential Republican opponents in a poll released Wednesday.

Quinnipiac University's latest poll found that Iowa Democratic Rep. Bruce Braley would defeat each of the six Republicans tested for this open-seat race. His closest competitor was former U.S. Attorney Matt Whitaker, whom Braley led 43 percent to 40 percent.

That bears out in Braley's leads over the other GOP contenders. He led by no less than 6 points against state Sen. Joni Ernst, radio host Sam Clovis, businessman Mark Jacobs, former Senate aide David Young and Bob Vander Plaats, an evangelical Christian activist who has not announced whether he will run for Senate.

Which Republican advances from a potential nominating convention may have the biggest effect on which party wins the seat. Still, Quinnipiac assistant polling director Peter A. Brown said in a release that Obama's "overwhelmingly negative job approval — including thumbs down from 15 percent of Democrats and 62 percent of independent voters — could be having an impact on the prospects for Iowa Democrats who do face the voters in 2014."

The poll of 1,617 registered voters was conducted Dec. 10-15. The margin of error was 2.4 points.